Plate clamp



March 25, 1941. LACURE HAL 2,236,146

PLATE CLAMP Filed June 19, 1940 3 Sheets-Sheet 1 Yg-j- 3Q (Bl 1 ,3

Mardl 1941- E. P. LACURE ETAL 2, 6,146

PLATE CLAMP v Filed June 19, 1940 3 Sheets-Sheet 2 gag- Eiga.

IIIIHIIHIHI 2mm La Hang 1 01 53 E. P. LACURE ETAL PLATE CLAMP Filed June19, 1940 3 Sheets-Sheet 5 Patented Mar. 25, 1941 UNETED STATES PATENTOFFICE.

PLATE CLAIHP Michigan Application June 19, 1940, Serial No. 341,354

19 Claims.

Our invention is a novel improvement in plate clamps for holding in apositive manner printing plates on the plate cylinders of printingpresses when said plates are of arcuate length sufficient to extend morethan halfway around the cylinder. Such plates must be entered on andremoved from the cylinders by slipping same over the ends thereof, andtherefore necessarily require the use of clamps which can be retractedbelow the plate supporting surfaces of the cylinders.

The principal object of our invention is to provide novel and eificientclamping mechanism I applicable to a reduced end of the cylinder, ashereinafter set forth, and having a plurality of retractible clampsthereon operable by simple means to retract the clamps from plateengaging position, into retracted position within the reduced endportion of the cylinder, said clamps :0 having a relative widearcuategripping edge not limited as has been heretofore the case, to thewidth of slots for the clamps customarily provided in the cylinder, ourmechanism entirely obviating the necessity of providing said slots inthe cylinders into which plate clamps may be retracted.

Other minor objects of the invention will be hereinafter set forth.

We will explain the invention with reference to the accompanyingdrawings, which illustrate one practical embodiment thereof, to enableothers familiar with the art to adopt and use the same; and willsummarize in the claims, the novel features of construction, and novelcombinations of parts, for which protection is desired.

In said drawings Fig. 1 is an elevation partly in section showing ournovel plate clamping mechanism applied to the reduced end of a platecylinder of a printing press, and showing the clamps in retracted orunlocked position with respect to the plate, in which position the platemay he slipped on or oif the cylinder over said mechanism.

Fig. 2 is a View similar to Fig. 1, but showing the clamps projectedinto plate clamping position.

Fig. 3 is an enlarged transverse section on the line 3--3, Fig. 1,showing the shift collar mounted on the reduced portion of the cylinder.

Fig. 4 is a side elevation of the shift collar, detached.

Fig, 5 is an enlarged transverse section on the line 4-4, Fig. 2.

(C1. Nib-378) Fig. 6' is a side elevation of the clip slide collar,partly in section.

Fig. 7 is a top plan view of the clamping mechanism with the parts inthe position shown in Fig. 2;

Fig- 8' is an enlarged rear elevation of the plate clip, detached.

Fig. 9 is a side elevation of the plate clip shown in Fig. 8.

Fig- 10 is a top plan view' of a clip slide, detached'.

' Fig. 11 is a side elevation of the clip slide shown in Fig. I0.

Fig. 12 is a. front elevation of the clip slide. The platecylind'erA isadapted to slidably support the arcuate printing plate B of usual formextending more than half-way around the circumference of the cylinder,which plate B must necessarily be slipped over the end of the cylinder Awhen inserting or removing the plate therefrom. One end of the platecylinder is provided with the usual fixed plate engaging devices (notshown), the opposite end of cylinder A being provided with our novelplate clamping mechanism, which is designed to have a wide gripping edgefor engagement with the plate, which edge is not limited to the width ofthe customary slots usually provided in such cylinders for receivingretractable plate clamps at said end of the cylinder, our mechanismhowever involving means whereby the plate clamps may be retracted belowthe plate supporting surface of cylinder A so as to permit printingplate B to be readily inserted or removed from the cylinder by slippingsame over the end of the cylinder to which our mechanism is applied.

As shown in Figs. 1, 2 and '7, plate cylinder A is provided with a platesupporting peripheral surface directly contacting the arcuate printingplate B; and one end of cylinder A is reduced in diameter as at A topermit installation of our plate clamping mechanism, thereby providing asquared shoulder A2 between the portion A and the main body of thecylinder normal to the axis of the cylinder.

Axially sl idably mounted on the reduced portion A of cylinder A,adjacent its outer end, is a shift collar 3 (Figs. 3 and 4) of exteriordiameter slightly less than the normal diameter of the body of cylinderA, whereby plate B may be slipped thereover when inserting orremovingsarne from cylinder A. In opposite sides of shiftcollar 3 arediametrically opposed cuts 3a3b forming recesses of substantial widthextending nearly to the ends of, said shift collar, the

ably slidably connected with shift collar 3. shown in Figs. 1 and 2,shift collar 3 is provided bottoms of the opposed cuts 3a-3b formingparallel surfaces adapted to engage cam shoes 4 of width to fit betweenthe side walls of the cuts 3a-3b so that same may slide along thebottoms of the said cuts, the length of the cam shoes being less thanthe lengths of the cuts as shown in Fig. 3. In the outer face of eachcam shoe 4 is a circular recess 4a of relatively large diameter adaptedto receive the head of a shift cam, and in the bottom of each recess 4bis a relative bore 40 for the passage of the shaft of the shift cam. Inthe bottoms of the cuts 3a,3b in shift collar 3 are longitudinallydisposed elongated slots 30 (Fig. 4) which are diametrically opposed,said slots 30 being of sufiicient diameter to receive the shaft of theshift cam, which shaft extends through the slots 30 and through atransversely diametrical bore A5 (Fig. 3) in the reduced portion A ofcylinder A.

As shown in Figs, 1, 2, 3 and 7, the shift cam preferably comprises ashaft 511 extending through bore A5 in reduced portion A, and throughthe opposed slots 30 in shift collar 3, said shaft 5a having eccentriccam heads 5b5c at its ends disposed respectively in the circularrecesses 4a of the cam shoes 4, the heads 5b--5c being locked to shaft511 in any desired manner, and thus serving to maintain the cam shoes 4in their respective cuts 3a3b in the shift collar 3. In one of the camheads 50, are a pair of spaced holes 501 accessible from the exterior ofthe shift collar 3, adapted to be engaged by a pronged wrench or othertool, whereby the cam shaft can be readily rotated to move the shiftcollar 3 axially of the reduced portion A from its retracted positionshown in Fig. 1, to its projected position shown in Fig. 2 to actuatethe plate clamps of the mechanism, as hereinafter described. One halfturn of cam shaft 5a will shift collar 3 from one extreme position tothe other.

On shaft extension A between shift collar 3 and the shoulder A2 is 'aclip slide collar 2 of exterior diameter slightly less than the internaldiameter of printing plate B,'collar 2 being yieldwith spaced holes 3dparallel with the axis of cylinder A, said holes registering with tappedbores 2bin clip slide collar 2, receiving bolts 9 having heads 9a housedin enlarged recesses 3a in the outer ends of bores 3d and carrying nutsSb to lock nuts 9c on the threaded portions 9d intermediate the ends ofthe bolts, the threaded shown, four such bolts 9 are arranged around theperiphery of the collars 2 and 3. Each bore 311 in shift collar 3 has anenlarged portion 3f at its inner end, and within said enlargement is acoiled spring Ill around the bolt interposed between the inner end ofsaid enlargement and the nut lib, said spring normally urging collar 3away from collar 2 so that the heads 9a of the bolts 9 will be seated atthe bases of the enlarged recesses 3c, the spring II! thus yieldablymounting the clip slide collar 2- with respect to shift collar 3.

In the face of clip slide collar 2 towards the shoulder A2, are a seriesof slots 20 (Fig. 6), the bases of which slots slope upwardly andoutwardly away from the shoulder A2. The lower portions of the slots areundercut asat 2d 'so as in and into the shoulder A2.

to retain clip slides 6 therein, the slots being substantially ofinverted T-shaped cross-section. As shown in Fig. 5, four such slots areprovided about the circumference of clip slide collar 2.

Within each of the slots 2c is a clip slide 6 (Figs. 1, 2, 6, 10, 11 and12) of normal width to fit between the side walls of slots 2c, andhaving T-shaped enlargements 6a at their lower ends to slidably engagethe correspondingly shaped enlargements 2d of slots 20, whereby theslides will be prevented from being lifted directly out of said slots.Preferably the outer face 6b of each clip 6 adjacent shoulder A2 isnormal to the axis of the cylinder, and extending through the clipslides 6, on the axis thereof, normal to the face 6b, is a bore 60having an enlarged inner end 6d adapted to receive the head of a bolt orscrew which connects the clip slide to its respective plate clip I. Bythe above construction each clip slide 6 is free to slide along theinclined lower face of the slot 20. towards or from the shoulder A2 ofthe cylinder, and in so doing the clip will be correspondingly shiftedradially of the axis of the cylinder A.

Mounted on each clip slide 6 is a plate clip 1 shown in Figs. 1, 2, 5,7, 8 and 9, said clip being of slightly arcuate shape, as shown, andhaving an inner end wall Ia normal to the axis of the cylinder Aprovided with a hole 1b for the reception of a bolt Ia: or the likewhereby the clip is secured to the vertical face 6b of clip slide 6 asshown in Figs. 1 and 2. At the lower end of the wall la is an arcuatebase portion 'Ic adapted to conform with the curvature of the reducedportion A of the cylinder, and in base 1c is an elongated slot 'Id, forthe purpose hereinafter described. At the upper end of the wall Ta is anarcuate flange 'Ie extending towards the shoulder A2, and the outer endof the flange 'Ie adjacent the wall A2 is beveled at an angle ofapproximately 30 to the vertical so as to engage the complementaryflanged end B of the printing plate B on the cylinder A; and theouterend is preferably knurled.

Secured to the shoulder A2 of the cylinder is a clip collar I having aweb preferably secured by bolts or the like passing through holes there-Clip collar I is provided with an outer annular flange Ia of sameexternal diameter as the main body portion of cylinder A, said flangeforming a continuation of the body of said cylinder and underlying andsupporting the beveled edge 13 of the plate B on the cylinder, theflange Ia projecting slightly be-- yond the beveled edge B of the plate,as shown in Figs. 1 and 2. The thickness of flange la is slightly lessthan the distance between adjacent faces of portions 70 and 1c of eachplate clip 'I. Clip collar [is also provided with an inner annularflange lb seating upon the reduced portion A of the cylinder A, saidflange extending .along said portion A and normally contacting theadjacent end of the base 1c of the plate clip 1, as shown in Fig. 1,when the parts are in unlocked position shown therein. The distancebetween the adjacent faces of flanges Ia and lb of clip collar I isslightly greater than the thickness of the base 1c of plate clip I.Extending diagonally downward through the outer flange Ia of clip collarI are pins or studs 8 which are preferably threaded into inclined tappedbores in the outer end of flange Ia, said pins or studs entering theelongated slots Id in the bases 1c of the respective plate clips I tomaintain the clips 'I aligned with the axes of their slots 20 in' collar2.

The unthr'eadedl portions of studs 8: which project into the slots Td;in the clips I prevent the latter from moving circumferentially, thuseliminating bending strains: on the studs 9.

In operation, assuming the parts are in position shown in Fig. 1 of thedrawings, the plate B is shoved onto the cylinder from the end over theretracted parts.- Suitable stops and clamps are carried by the cylinderto hold. the endv of plate B opposite from our clamping mechanism, thesebeing of the usual style and not shown in our present application. Whenthe plate is en tered onto the cylinder the shift cam 5a;-5b-'-5c isrotated by a wrench having projections which enter the two holestdtherein. One non-circular hole however could be used instead of thetwo holes Ed. As the cam shaft- 5a isrotated the eccentric head's 5b-5C-force the; shift collar 3- toward the shoulder A2 of the cylindercarrying with it, by means of the yieldably mounted studs 9 the clipslide collar 2. As collar 2' moves toward the end B of the plate, theangular slotsZc in the collar 2, already engaged with angular tongues toin the clips 6 and I, force: the clips 6 and l to. move radially ofcylinder A until the projecting flange to will clear the flange la. ofclip collar l The outer end of base 'lc will then engage the undersurface of the flange la of collar l, and further rotation of cam shaft501. will force the collars 2 and 3' and; the clips 6 and T axiallyuntil the flanges 1c of clips 1 contact the beveled end B of the plate.The springs In of studs 9 equalize. the pressures between theclips 5--land the plate B. In previous devices for this purpose, the plategripping portions of the clips I were limited to the width of slotsformed in the cylinder A. Our device: however permits use of a widegripping edge, not limited to the width of slots in the cylinder A; alsosaid slots in the cylinder in previous devices are entirely eliminated.

For small differences in thelengths of plates B, the studs 9 may berotated in the collar 2- to shorten or lengthen. the travel of flangesTe of the clips I, said studs 9. being locked in position by the locknuts 9e after the adjustment is made. Also to equalize the springpressure the springs It] may be compressed or expanded by adjusting thenuts lib-90. Adjustments of about A." or less are sufficient for thesesmall variations. However, sometimes a pressman makes replacements ofplates which are considerably shorter than the maximum length asprovided. In this case a collar marked A4 (Figs. 1 and 2) may beprovided between the clip collar l and the shoulder A2 of the cylinder.This applies to a change from a plate say 16" long to a plate 14 long orin other words, a make-up of 8 column 12 ems to a '7 column make-up.

We claim:

1. In combination, a plate cylinder having a cylindrical platesupporting surface and having an axially disposed reduced portion; amember within the reduced portion forming a continuation of thesupporting surface and adapted to underlie one end of a printing platedisposed thereon, said member having an annular recess in its outer end;a collar of diameter smaller than the supporting surface slidablymounted on said reduced portion, and having portions of its outer faceinclined outwardly away from the said member; substantially U-shapedplate clips disposed between the collar and member and normally belowthe plate supporting surface and having portions engaging said inclinedportions of the collar said clipsnormally seating upon the reducedportion: with their legs directed towards the memher; and. means forshifting the collar towards the member whereby theclips will be movedoutwardly' and axially to permit thelegs of the clips to telescope thesaid member with one leg of each clip overlying the outer face of themember to engage the end of the printing plate.

2.-In. a combination as. set forth in claim 1, a removable. collar insaid reduced portion interposed between the member and the end of thereduced portion, and forming a continuation of the plate supporting.surface to: permit adjustment of the member" to suit plates of variouswidths.

3.. In: a combination as set forth in claim 1, said collar shiftingmeans comprising a slidable shift collar on the reduced. portion; cammeans for shitting the shift collar; and yieldabl'e means connecting theshift collar with the: first mentioned collar.-

4; In a combination asset forth in claim 1, said collar shifting: meanscomprising a slidable shift collar on thereduced portion havingdiametrically opposed. cam shoes slidably mounted therein; a cam. shaftvextending through said shift collar, cam shoes,- and through adiametrically disposed bore in said reduced portion and havingeccentricall'y disposed heads thereon engaging recesses in the camshoes; means for rotating the shaft; and yieldable means connecting theshift collar with the first mentioned collar.

5'. In combination, a plate cylinder having a cylindrical platesupporting surface and having an. axially disposed reduced portion; amember within the reduced portion forming a continuation of thesupporting surface and adapted to underlie one end of a printing platedisposed there-- on; said member having an annular recess in its outerend; a collar of diameter smaller than the platesupporting surfaceslidably mounted on said reduced portion, and having a series of slotsin its outer face extending from its end adjacent the member, thebottoms of said slots being inclined outwardly away from the saidmember; slides engaging said; slots; plate clips carried by said slidesdisposed between the collar and member, and having. base flangesnormally seating upon the reduced portion, and having outer flangesnormally' disposed. below the plate supporting surface; and means forshifting the collar towards the member whereby the clips will be movedoutwardly and axially to permit the base flanges thereof to enter theannular recess in the member whereby the outer flanges of the clips willoverlie the outer face of the member to engage the end of the printingplate.

6. In a combination as set forth in claim 5, means for maintaining theclips in alignment with their respective slots.

7. In a combination as set forth in claim 5, a removable collar in saidreduced portion interposed between the member and end of the reducedportion, and forming a continuation of the plate supporting surface topermit adjustment of the member to suit plates of various widths.

8. In a combination as set forth in claim 5, said collar shifting meanscomprising a slidable shift collar on the reduced portion; cam means forshifting the shift collar; and yieldable means connecting the shiftcollar with the first mentioned collar.

9. In a combination as set forth in claim 5, said collar shifting meanscomprising a sildable shift collar on the reduced portion havingdiametrically opposed cam shoes slidably mounted therein; a cam shaftextending through said shift collar, cam shoes, and through adiametrically disposed bore in said reduced portion and havingeccentrically disposed heads thereon engaging recesses in the cam shoes;mean-s for rotating the shaft; and yieldable means connecting the shiftcollar with the first mentioned collar.

10. In combination, a plate cylinder having a cylindrical platesupporting surface and having an axially disposed reduced end portionforming a shoulder; a member within the reduced portion secured to saidshoulder and having an outer annular flange forming a continuation ofthe plate supporting surface adapted to underlie the end of a printingplate disposed thereon; said member having an inner annular flangeseat-ed upon the reduced end portion; a collar of diaameter smaller thanthe plate supporting surface slidably mounted on said reduced endportion, and having a series of slots in its outer face extending fromits end adjacent the member, the bottoms of said slots being inclinedoutwardly away from said member; slides engaging said slots adapted tobe shifted radially outwardly as the collar is shifted axially towardsthe member; plate clips carried by said slides disposed between thecollar and member and having base flanges normally seating upon thereduced end portion and contacting the ends of the inner flange of themember, said plate clips having outer flanges normally disposed oppositethe outer flange of the member; and means for shifting the collartowards the member whereby the plate clips will be moved outwardly topermit the base flanges of the clips to enter between the inner andouter flanges of the member, and the outer flanges of the plate clips tooverlie the out-er flange of the member to engage the end of theprinting plate.

11. In a combination as set forth in claim 10, means for maintaining theplate clips in alignment with their respective slots.

12. In a combination as set forth in claim 10, studs on the outer end ofthe outer flange of the member entering slots in the base flanges of theplate clips for maintaining the plate clips in alignment with theirrespective slots.

13. In a combination as set forth in claim 10, a removable collar insaid reduced portion interposed between the member and shoulder andforming a continuation of the plat-e supporting surface to permitadjustment of the member to suit plates of various widths.

14. In a combination as set forth in claim 10, said collar shiftingmeans comprising a slidable shift collar on the reduced end portion; cammeans for shifting the shift collar; and yieldable means connecting theshift collar with the first mentioned collar.

15. In a combination as set forth in claimv 10, said collar shiftingmeans comprising a slidable shift collar on the reduced portion havingdiametrically opposed cam shoes slidably mounted therein; a cam shaftextending through said shift collar, cam shoes, and through adiametrically disposed bore in said reduced end portion and havingeccentrioally disposed disk-heads thereon engaging circular recesses inthe cam shoes; means for rotating the shaft; and yieldable meansconnecting the shift collar with the first mentioned collar.

16. In combination, a plate cylinder having a cylindrical platesupporting surface and having an axially disposed reduced portion; saidsupporting surface having an annular recess in its outer end underlyingone end of a printing plate disposed thereon; a collar of smallerexternal diameter than the plate supporting surface slidably mounted onsaid reduced portion; plate clips disposed between the collar and platesupporting surface and having base flanges normally seating upon thereduced portion and having outer flanges normally disposed below theplate supporting surface; means operated by the collar when same ismoved axially towards the plate supporting surface whereby the clipswill be moved outwardly and axially to permit the base flanges thereofto enter the annular recess in the end of .the plate supporting surfaceand the outer flanges of the clips to overlie the plate supportingsurface and engage the end of the printing plate; and means for movingthe collar.

17. In a combination as set forth in claim 16, said collar moving meanscomprising a slidable shift collar on the reduced portion; cam means forshifting the shift collar; and yieldable means connecting the shiftcollar with the first menrecesses in the cam shoes; means for rotatingthe shaft; and yieldable means connecting the shift collar with thefirst mentioned collar.

19. In a combination as set forth in claim 16, said collar moving meanscomprising a slidable shift'collar on the reduced portion havingdiametrically opposed cam shoes slidably mounted therein; a cam shaftextending through said shift collar, cam shoes, and through adiametrically disposed bore in said reduced portion and havingeccentri-cally disposed disk-heads thereon engaging circular recess-esin the cam shoes; means for rotating the shaft; and spring pressed boltsadjustably connecting the shift collar with the firs-t mentioned collar.

EARL P. LACURE. ALBERT J. CARPENTER, JR.

ii-O

